Diestock



Jan. 3, 1928. 1,655,072

H. W. OSTER ET AL DIESTOCK Filed gplgil 19, 1924 2 Sheets-Sheet 1 INVENTORJ Jlflwmn U 06 fax and By 6262777 Z7. J/eef/z 861%. m 4/ A TTORNEKS Jan. 3, 1928.

H. W. OSTER ET AL DIESTOCK Filed April 19. 1924 2 Sheets-Sheet 2 26 IN VEN TORJ.

G CEL BY 6/6121? ZZ 53 0M 7 9 ATTORNEYS Patented Jan. 3, 1928.

UNlTED STATES HERMAN W. OSTER AND GLENN D. SLEETI-I,

OSTER MANUFACTURING COMPANY, OF

OHIO.

OF CLEVELAND, OHIO, ASSIGNORS TO THE CLEVELAND, OHIO, A CORPORATION OF DIESTOCK.

Application fi ed April 19, 1924.

The present improvements, relating, as indicated, to die stocks, have more particular regard to the provision in thread cutting devices of the type known as die stocks of means whereby the dies may be readily adjusted to cut threads slightly over size or under size, as desired. In various pipe fitting and like operations, it frequently becomes desirable thus to cut a thread of a diameter slightly greater or less than the standard dimensions for which different sets of dies are provided. The object of the presentinvention, accordingly, is to provide a simple and easily operable attachment for die stocks whereby the setting of the dies in such stock may be slightly varied in one direction or the other thus to accommodate the same to the cutting of oversize or undersize threads. Our improved feature of construction is equally adaptable to any type of die stock in which chaser dies are employed, whether such stock be of the simple type in which the dies are held in fixed position during the cutting operation, or of the taper thread cutting type in which the dies are caused automatically to recede during the cutting operation so as to cut a thread on a slight incline as is desirable in pipe threading work.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings Fig. 1 is a front elevation of one form of what may be termed a simple die stock wherein the present improvements have been incorporated, such die stock being of the pulral type, i. e. carrying several sets of Chasers for cutting threads of different standard size; Fig. 2 is a central axial section of such die stock, as indicated by the line 22, Fig. 1; Fig. 3 is a central axial section of such die stock on a differentplane as indicated by the line 33 of Fig. 1; Fig. & is a section of a detail, the plane of the sec tion being indicated by the line l.{l of Fig. 1; Fig. 5 is a transverse section of a detail,

Serial No. 707,572.

such section being indicated by the section lines 5-5, Figs. 2 and 3; Fig. 6 is a front elevation of one type of so-called taper thread cu ting die stock wherein the present improved adjusting feature has been incorporated; Fig. 7 is a central axial section of such die stock taken on the two angularly related radial planes indicated by the line Fig. 6; Fig. 8 is a sectional view of a detail, the plane of the section being indicated by the line 88, Fig. 6; Fig. 9 is a transverse sectional view of the same detail, as indicated by the line 99, Fig. 8; and Fig. 10 is a more or less diagrammatic representation of a chaser die and co-operating element whereby it is radially positioned in the die stock.

Referring first of all to the form of die stock shown in Figs. 1 to 5 inclusive, the body 1 it will be seen is of hollow hexagonal form, such body being provided with two oppositely projecting sockets 2 adapted to receive handles 3 as usual. The respective parallel sides of the hexagonal body 1 are providee with aligned openings 4. and 5. such opening having fitted thereto a guide ring (5 of appropriate diameter for the rod or pipe upon which the corresponding set of thread cutting dies 7 is designed to operate. The latter are secured to the corresponding outer face of the body 1 by means of a housing 8. Such housing comprises in effect an annular plate from which rise four bosses 9 provided with radial slots 10, in which the corresponding dies 7 are held.

The inner or cutting faces of the dies projeet within the opening 5, as shown in Fig. 1, so as to engage with a pipe or like article introduced through guide ring 6, as will be readily understood. while the rear ends of said dies project slightly beyond the outer ends of the corresponding slots 10 into position to engage with pins 12 that are mounted in bosses l3 projecting radially from body 1, such pins being generally parallel with the axis of the corresponding pair of openings 4- and 5. The outer ends of the dies, which thus engage with or rather press against pins 19,, are inclined transversely of radial lines passing through said dies. In effect an eccentric engagement between the dies and pins is thus obtained, as the result of which rotative adjustment of plate 8 serves to dis place said dies in a radial direction. The

. same direction so that all the dies will be simultaneously displaced equal amounts.

. For the purpose of rotatably adjustably securing plate 8 to thebody, such plate is provided at diametricall opposite points. with arcuate slots 15 gsee Fig. 5) and through such slots pass set-bolts 16 that are threaded in the body, washers 17 being interposed between the heads 16 of such bolts and the plate. By loosening the set bolts, the plate may be rotated slightly in one direction or the other, such that when the chaser dies are forced outwardly into contact with pins 12, they will be positioned to out a thread slightly over size or under size. as may be required. Upon then tightening the bolts 16, the plate 8 will clamp the dies against the body with suflicient force to prevent their incidental dislodgment. The effect of rotative adjustment of the plate in the fashion just described is clearly illustrated in Fig. 10, where the die is shown in full lines in what may be termed its normal position, while in dotted out-line it is shown in two alternative positions.

The axial sectional view of the die stock shown in Fig. 3, might equally well constitute the corresponding section of a single, instead of a plural die-stock. In other words the pair of aligned openings I and 5 appearing in this figure would be the only openings in the body 1, while the other parts would be substantially identical with those found in the plural die-stock shown in Figs. 1 and 2.

In Figs. 6 to 9, inclusive, the improvements of present interest are shown as incorporated in one typical form of die stock intended for cutting taper threads as is required in pipe fitting work. The form of taper thread cutting tool thus illustrated is particularly well adapted for the inclusion of such improvements, as will appear.

The die stock body 20 which carries the chaser dies 21, as before is provided with oppositely directed handle receiving bosses 22. Connected with said body as by an external lead screw 23 is a tubular member 24, the outer end of which is provided with a work holding or centering device. The latter is in the main of standard construction, comprising a plurality of jaws or dies 25 that are opened or closed, as desired, by rotation of a handled cam or scroll plate 26. The tubular member 24 also carries a shell 27 that slidably fits within the body 22, such shell being held in place by means of a flange 28 on its outer end and serving to protect the interior threads on said member 24. From the foregoing construction it will be seen that when the annular member 24 is secured to the work by closing jaws 25 thereon and the body 20 then rotated, the

'ment longitudinally or furthermore lead screw 23 will cause such body to move longitudinally of said member and thus of the work.

Surrounding the member 2-l is a ring 30 held in place against a shoulder-J31 by means of a collar 32 so as to be freely rotatable about said. member 24: but held against moref the same. Secured to circumferentially spaced radially projecting portions 33 ofthe ring 30 are pins one for each die 21, that project genera V parallel with the axis of the body, their outer ends passing through apertured guides that project radially from such body, such guides occupying the same circumferentialpositions about the body as do the projections 38 about the ring 30. The extremities of the pins are provided with heads 36 (see Fig. '7) that prevent the same from being disengaged from the guides and the inner faces of said pins incline longitudinally outwardly from such forward ends to ards the ring 30, as likewise shown in Fig. 7. Such inwardly directed faces are rounded transversely so as to have in effect a line contact only with the outer ends of the chaser dies 21.

Such outer die ends, just as in the case of the previously described simpler forms of die stock, are inclined all in the same direction transversely of radial lines passing through said dies and just as before said dies are held against the face of die stock body 20 by means of a plate 37 that is secured to said body so as to be rotatably adjustable about the axis thereof through a limited arc. the dies being held in'radial slots 38 formed in bosses 39 that rise from said plate. The latter is thusrotatablysecured to the die stock body by means of set bolts 40 passing through arcuate slots 41 and threaded. in such body, washers 42 being interposed between the heads of the bolt and plate.

From the foregoing construction, it will be seen that rotative adjustment of plate 3? will vary the normal position of the chaser dies 21, i. e., the position which they occupy when the body 20is in fully extended position, as shown in Fig. 7, and the outer ends of such dies are pressed against the inwardly directed faces of the corresponding pins 34. In other words, such dies may be set to cut a thread slightly over or under size, as desired. Incidentally to the thread cutting operation the rear ends of the dies will travel along the inclined inwardly directed faces of pins 34-, being held at all times against such faces by the pressure of'the work on their cutting faces, and as a result such'dies will gradually recede to cut a taper thread, as will be readily understood.

Since it will not be permissible, as in previously described constructions, to clamp the dies forciblyiagainst the face of body 20. if they are to be left thus free to recede during the cutting operation, means are provided for frictionally retaining the dies in place so that they will not accidentally move inwardly pending the initiation of the cutting operation. Such means, as shown in Fig. '7, will conveniently take the torm o l small balls 43 that are held in holes 44 formed in the die body directly beneath the spaces which are occupied by the several dies, a compression spring 4L5 backof each such ball serving to press the same against the corre sponding die.

'Other modes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

lVe therefore particularly point out and distinctly claim as our invention 1. In a thread-cutting device of the character described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so as to be rotatably adjustable about the axis thereof through a limited are, said plate engaging with said dies to hold the same in radially movable relation to said body, and members projecting from the latter in fixed rotative relation to said plate, said members and dies having eccentric engagement, whereby rotative adjustment of said plate serves to radially displace said dies.

2. In a thread-cutting device of the character described, the combination of asuitable body, chaser-dies carried by said body, plate secured to said body so as to be rotatably adjustable about the axis thereof through a limited arc, said plate engaging with said dies to hold the same in radially movable relation to said body, and a plurality of pins, one for each die, projecting from said body parallel with the axis thereof, said pins and dies having eccentric engagement, whereby rotative adjustment of said plate serves to radially displace said dies.

3. In a thread-cutting device oi? the character described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so as to be rotatably adjustable about the axis thereof through a limited arc, said plate engaging with said dies to hold the same in radially movable relation to said body, and a plurality of pins, one for each die, projecting from said body parallel with the axis thereof and engaging with the outer die-ends, said outer die-ends which engage with such pins being inclined at an angle, whereby rotative adjustment of said plate serves to radially displace said dies.

4. In thread-cutting device of the character described, the combination of a suitable body chaserdies carried by said body, a

plate secured to said body so :as to be rotata 'bly adj ustablc about the axis thereof through a limited are, said plate engaging with said dies to hold the sai-ne in radially movable relation to said body, and a plurality of pins. one tor each die, projecting from said body generally parallel with the :axis thereof, said pins having their inwardly directed faces transversely rounded and the outer die-ends, which engage with such faces, being inclined ac an angle, whereby rotative adjustment of said plate serves to radially displace said dies.

5. In a thread-cuttin device of the character described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so as to be rotatt bly adjustable about the axis thereof through a limited are, said plate having its inner face torn-red with approximately radial slots wherein said dies are held, and a plurality of pins, one for each die, projecting from said body parallel with the axis thereof, said pins and dies having eccentric engagement, whereby rotative adjustment of said plate serves to radially displace said dies.

6. In a threadcutting device of the character described, the combination of a suitable body, chaser-dies carried by said body. a plate appliedto said body and having its inner face formed with approximately radial. slots wherein said dies are held, said plate being also provided with arcuate slots. set-bolts passing through such slots and threaded in said body, whereby said plate may be clamped to the latter in desired rot-atably adjusted position, and a plurality of pins, one for each die, projecting from said body parallel with the axis thereof, said pins and dies having eccentric engagement, whereby rotative adjustment of said plate serves to radially displace said dies.

7. In a thread-cutting device of the character described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so as to be rotatably adjustable about the axis thereof through a limited are, said plate engaging with said dies to hold the same in radially movable relation to said body, an annular work-holding member connected with said body by a lead-screw, a pluralit 1 of longitudinally tapered pins, one for each die, rotatable with said body but held against longitudinal movement relatively to said member, said pins projecting from said body parallel with the axis thereof and said pins and dies having eccentric engagement, whereby rotative adjustment of said plate serves to radially displace said dies.

8. In a thread-cutting device of the char acter described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so as to be rotatably adjustable about the axis thereof lll) through a limited are, said plate engaging with said dies to hold the same in radially movable relation to said body, an annular work-holding member connected with said body by a lead-screw, a ring rotatable upon said member, but held against movement longitudinally of its axis, and a plurality of longitudinally tapered pins, one for each die, carried by said ring, said pins project- 'ing from said body parallel with the axis thereof and said pins and dies having eccentric engagement, whereby rotative adjustment of said plate serves to radially displace said dies.

9. In a thread-cutting device of the character described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so as to be rotatably adjustable about the axis thereof through a limited arc, said plate engaging with said dies to hold the same in radially movable relation to said body, an annular work-holding member connected with said body by a lead-screw, a ring rotatable upon said member but held against movement longitudinally of its axis, and a plurality of longitudinally tapered pins, one for each die, carried by said ring, the said outer the ends which engage with such pins being inclined at an angle, whcreby rotative adjustment of said plate serves ,to radially displace said dies.

10. In a thread-cutting device of the character described, the combination of a suitable body, chaser-dies carried by said body, a plate secured to said body so. asto be rotatably adjustable about the axis thereof through a limited are, said plate engaging with said dies to hold the same in radially movable relation to said body, an annular workholding member connected with said body by a lead-screw, a ring rotatable upon said member but held against movement longitudinally of its axis, and a plurality of longitudinally tapered pins, one for each die, carried by said ring, said pins having their inwardly directed faces transversely rounded and the outer die-ends, which engage with such faces, being inclined at an angle, whereby rotative adjustment of said plate serves to radially displace said dies.

11. The combination of a work-holding member,-a die-holding body connected with said member by a lead-screw, whereby rotation of said body serves to move thesame longitudinally of said member, a ring rotatable upon but held against movement longitudinally of said member, a plurality of chaser dies carried by a body, the outer ends of said dies being inclined transversely of radial lines passing through said dies, a plate secured to said body so as to be rotat ably adjustable about the axis thereof through a limited arc, said plate having its inner face formed with radial slots wherein said dies are held, and a plurality of pins, one for each die, attached to said ring and projecting from said body in alignment with the axis thereof, the inwardly directed faces of said pins which engage with the outer die-ends inclining longitudinally outwardly from their free ends towards said ring and being transversely rounded.

Signed by us this 16th day of April, 1924;,

- HERMAN W. OSTER.

GLENN D. SLEETH. 

